Alcohol has been extensively used as a sleep aid by a large portion of the general population. 28 percent of individuals who have trouble sleeping have said that they will consume small amounts of alcohol at night to help them fall asleep.
While alcohol does limit the amount of REM sleep in the first parts of sleep, it does have a quick effect on your brain allowing it to enter into non-REM sleep. Alcohol is metabolized quickly and the level of alcohol in your blood quickly drops which will allow your body to enter into the REM stage of sleep later in the night.